640619520 has 176 divisors, whose sum is σ = 2069271360. Its totient is φ = 169148416.

The previous prime is 640619513. The next prime is 640619527. The reversal of 640619520 is 25916046.

It is an interprime number because it is at equal distance from previous prime (640619513) and next prime (640619527).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640619527) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2749324 + ... + 2749556.

Almost surely, 2^640619520 is an apocalyptic number.

640619520 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 640619520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1034635680).

640619520 is an abundant number, since it is smaller than the sum of its proper divisors (1428651840).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

640619520 is a wasteful number, since it uses less digits than its factorization.

640619520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 440 (or 422 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 33.

The square root of 640619520 is about 25310.4626587504. The cubic root of 640619520 is about 862.0518520424.

The spelling of 640619520 in words is "six hundred forty million, six hundred nineteen thousand, five hundred twenty".